210100220000021 has 4 divisors (see below), whose sum is σ = 226261775384652. Its totient is φ = 193938664615392.

The previous prime is 210100220000009. The next prime is 210100220000059. The reversal of 210100220000021 is 120000022001012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 34066074658225 + 176034145341796 = 5836615^2 + 13267786^2 .

It is a cyclic number.

It is not a de Polignac number, because 210100220000021 - 2¹⁰ = 210100219998997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210100219999957 and 210100220000011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210100220060021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8080777692296 + ... + 8080777692321.

It is an arithmetic number, because the mean of its divisors is an integer number (56565443846163).

Almost surely, 2^{210100220000021} is an apocalyptic number.

It is an amenable number.

210100220000021 is a deficient number, since it is larger than the sum of its proper divisors (16161555384631).

210100220000021 is a wasteful number, since it uses less digits than its factorization.

210100220000021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16161555384630.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 210100220000021 its reverse (120000022001012), we get a palindrome (330100242001033).

The spelling of 210100220000021 in words is "two hundred ten trillion, one hundred billion, two hundred twenty million, twenty-one", and thus it is an aban number.